Somatostatin is a tetradecapeptide found deficient in patients with Alzheimer's Disease (AD). We have continued with the analysis of data gathered to described the pharmacokinetics of L 363, 586 in normal and Alzheimer's Disease subjects. Although levels of the somatostatin analog were below the assay sensitivity (RIA; 5.0pg/ml) in the CSF, its positive effects on the memory of some patients were evident. Disposition of L 363, 586 in both the normal subjects and Alzheimer's Disease was found to be similar. The 20% or so of changes observed in the clearance of AD patients and distribution volume were not statistically significant (p greater than 0.1). This suggests that future investigations with this analog may be designed based on same disposition profile observed in disease and normal subjects and that higher concentrations in CSF may be necessary for it to show its neuromodulatory properties.